• 05-11-2011, 10:55 AM
    dingus
    subwoofer... passive or powered?
    which is the better performer in terms of accuracy, or is it a moot point?

    i'm considering adding a dedicated sub that can get down in the mid-20hz. my receiver should be able to drive a passive sub without problem, and if not i have some beefy power amps that can do the job without question. my ht rig is a music first system, so i prefer sound quality over quantity.
  • 05-11-2011, 11:29 AM
    pixelthis
    1 Attachment(s)
    Quote:

    Originally Posted by dingus
    which is the better performer in terms of accuracy, or is it a moot point?

    i'm considering adding a dedicated sub that can get down in the mid-20hz. my receiver should be able to drive a passive sub without problem, and if not i have some beefy power amps that can do the job without question. my ht rig is a music first system, so i prefer sound quality over quantity.

    Most subs are powered these days. THERES something called a "plate amp" on
    the back, and most of these are quite good.
    My sub came with a 600w amp, which died when a friend borrowed it, so I
    canabalized another sub for its 130w amp, which works fine in my small room.
    If you really want a power amp or something else to power a sub, you can buy a
    kit and build your own, and power it anyway you want, or buy a sub and take the amp off of the back.
    But it will give little if any improvement over the plate amp that comes with most subs,
    just complicate the plumbing, is all.:1:
  • 05-11-2011, 11:48 AM
    markw
    You're gonna have to figure on a low-pass filter (at least) somewhere in the mix.
  • 05-11-2011, 12:29 PM
    GMichael
    Both can get you very nice results. I built a passive sub and mated it with a 4000 watt external amp. It works great. But I've also heard some very nice subs with the plate amps built in.
    The build quality will make the bigger difference.
  • 05-11-2011, 12:30 PM
    bfalls
    I would recommend powered over passive. I don't know of any receivers which have a powered output for a sub. Connecting a passive sub to a receiver would require connecting your mains via the sub's speaker level inputs, thus sharing the power from the main channels with the sub.

    Having a powered sub would reduce the strain on the main channels and free up power for mid and high freq reproduction. Especially if you are considering a sub which can reproduce appreciable levels in the 20Hz-30Hz range which takes a low of power.

    Most receiver can't even produce rated output with all channels driven. Adding a sub to the mix would reduce the available power to all channels that much more. Unless you have a flagship receiver weighing 45+lbs (due mostly likely to a larger transformer) and 120+W/ch go with a powered sub. If you're a bass guy who likes bass very low and very loud go with a good powered sub.

    If you can't swing the cash for a good powered sub. You can still get decent bass with a lesser one and utilize corner placement. From what I've read, corner placement can increase perceived output by 6 - 9 db.
  • 05-11-2011, 12:56 PM
    GMichael
    Yeah, I wouldn't drive the sub with your receiver's amp. You'll want another amp. Either a built in one or external will work.
  • 05-11-2011, 02:46 PM
    Sir Terrence the Terrible
    Quote:

    Originally Posted by bfalls
    I would recommend powered over passive. I don't know of any receivers which have a powered output for a sub. Connecting a passive sub to a receiver would require connecting your mains via the sub's speaker level inputs, thus sharing the power from the main channels with the sub.

    Having a powered sub would reduce the strain on the main channels and free up power for mid and high freq reproduction. Especially if you are considering a sub which can reproduce appreciable levels in the 20Hz-30Hz range which takes a low of power.

    Most receiver can't even produce rated output with all channels driven. Adding a sub to the mix would reduce the available power to all channels that much more. Unless you have a flagship receiver weighing 45+lbs (due mostly likely to a larger transformer) and 120+W/ch go with a powered sub. If you're a bass guy who likes bass very low and very loud go with a good powered sub.

    If you can't swing the cash for a good powered sub. You can still get decent bass with a lesser one and utilize corner placement. From what I've read, corner placement can increase perceived output by 6 - 9 db.

    B, this is not correct. You use the LFE output directly to an amp which amplifies the signal to the speakers. All of my H-PAS subs are passive, and that is how I hook them up

    Processor's> LFE output > Audyssey sub EQ > amp to speaker.

    I do not think either passive or active subs offer any advantage over the other. I use both types, and get great sound from both types. Calibration and room placement are more important than active or passive.
  • 05-11-2011, 03:39 PM
    Poultrygeist
    I have an outdoor passive sub which is driven off the amp speaker taps ( speaker level connection ), The sub then passes the signal on to two sat speakers which run full range.

    I'm building two 15 " H frame OB bass drivers which are passive in the sense that they are externally powered by a Dayton APA150 stereo amp which has it's own crossover control.
  • 05-11-2011, 04:12 PM
    bfalls
    Quote:

    Originally Posted by Sir Terrence the Terrible
    B, this is not correct. You use the LFE output directly to an amp which amplifies the signal to the speakers. All of my H-PAS subs are passive, and that is how I hook them up

    Processor's> LFE output > Audyssey sub EQ > amp to speaker.

    I do not think either passive or active subs offer any advantage over the other. I use both types, and get great sound from both types. Calibration and room placement are more important than active or passive.

    My bad. I misread. I thought he wanted to go directly from his receiver. I use a similar config with my passive ACI Saturn compound sub, LFE out, Yamaha M-65 amp, sub with one system. Also to bi-amp my Legacy Focus' 3-12" woofers. UMC-1 LFE out, XPA-5, sub.
  • 05-11-2011, 04:24 PM
    dingus
    the receiver is the Pioneer in my sig, a 7.1 x 130wpc @ 8 ohm, 160wpc @ 6 ohm. even if that wont do it i can use one of my Yamaha amps, B-2x (170wpc) or M-2 (210wpc). even so, i wouldnt be opposed to a powered sub.

    Quote:

    Originally Posted by Sir Terrence the Terrible
    Calibration and room placement are more important than active or passive.

    thats good info. i've never used a separate sub before. i got used to having all the bass i could handle with the 4x12" woofers in a pair of AR9's. what about ported -vs- acoustic suspension?
  • 05-11-2011, 08:58 PM
    harley .guy07
    There are plenty of subwoofers available that can fill a large room that cna go in your corner or otherwise. SVS is one I would recomend. also Hsu subwoofers are a good company from what I have read. You can build your own custom sub in your home it just takes the nohow in the driver selection,amp,and enclosure that you want to use. I once installed a trio of EV 18" subs with a QSC amplifier running 2 ohm with fan cooling in a guys basement and it was thunderous but he would turn them off for music which I don't blame him they were not meant for that anyway. My point is that the amount of bass you produce is not the quest it is how well and how detailed you can do it without disrupting the sonic flow from your main speakers and that they meat at grounds that you you cannot tell one from the other. That is the ultimate test of a sub, most cannot do it in that they put out something that gives them away like a sonic signature or a difference to the mains. Buts thats for music home theater is a different battle all together.
  • 05-12-2011, 01:05 PM
    pixelthis
    Quote:

    Originally Posted by GMichael
    Yeah, I wouldn't drive the sub with your receiver's amp. You'll want another amp. Either a built in one or external will work.

    THERES' nothing wrong with it, an amp is an amp.
    BEFORE I replaced the plate amp on my sub, I used one of the spare channels
    on my receiver to power my sub. WORKED fine, but you are correct in that it
    is not the preferred way of doing things. A good patch in a pinch, tho.
    ALSO, no reason you can't use an external amp to power a sub, just a waste of a decent amp, is all.
    A PLATE AMP IS DESIGNED to drive a sub, and it just works a lot better.:1:
  • 05-12-2011, 01:16 PM
    pixelthis
    1 Attachment(s)
    Quote:

    Originally Posted by dingus
    the receiver is the Pioneer in my sig, a 7.1 x 130wpc @ 8 ohm, 160wpc @ 6 ohm. even if that wont do it i can use one of my Yamaha amps, B-2x (170wpc) or M-2 (210wpc). even so, i wouldnt be opposed to a powered sub.


    thats good info. i've never used a separate sub before. i got used to having all the bass i could handle with the 4x12" woofers in a pair of AR9's. what about ported -vs- acoustic suspension?

    A "PORTED" sub tends to produce a "huffing" sound as it pumps air in and out of its port, although this isn't a problem most of the time, but on a poorly designed sub it can
    be a bother.
    MAKING speakers is the last bastion of audios roots, which started out with kits to
    build amps, etc. AND its fun, but mostly a waste of time, really.
    A sub already built is just going to work a lot better. Only reason I messed with mine
    is that I really love my sub, it is very musical, and besides, if you can fix something
    that is a 1200$ item instead of chucking it, you do so.
    Mine is either a clone or a copy of a BOB carver mini sub, don't think you could easily
    replace it, not very cheaply, anyway.
    AS FOR PORTED vs sealed enclosure, I prefer the sealed type, just easier to place,
    IMHO.:1:
  • 05-27-2011, 02:31 PM
    N. Abstentia
    Your receiver will never be able to power a sub properly. Get a powered sub, or an outboard amp if you get a passive sub.
  • 05-28-2011, 12:09 PM
    dingus
    i just pulled the trigger on an M&K V-1b, 12" powered sub. its a sealed enclosure and seems to be integrating nicely into the system so far. still a little bit of tweaking left to do before i'm totally happy with it.
  • 05-28-2011, 01:05 PM
    GMichael
    Next step is a BFD. For under $100 it's a huge addition to any sub.
  • 05-28-2011, 02:34 PM
    dingus
    whats a BFD?
  • 05-28-2011, 06:20 PM
    GMichael
    It's made to be a feedback destroyer to prevent feedback at live shows. But it turns out to be a great EQ for subwoofers as well.
    Check this link for a better explanation.
    http://bfdguide.ws/
  • 05-28-2011, 07:59 PM
    dingus
    ah yes, thank you!
  • 05-29-2011, 09:17 AM
    pixelthis
    1 Attachment(s)
    Quote:

    Originally Posted by N. Abstentia View Post
    Your receiver will never be able to power a sub properly. Get a powered sub, or an outboard amp if you get a passive sub.

    AU CONTRAIR, an amp is an amp, and my receiver is (or was)
    7.1 and my system 5.1. I RAN my sub off of one of the spare amps
    for months, until another plate amp availed itself to me.
    My receiver was 125wpc, and I didn't need nearly that much in
    my small listening room, NEVER had a problem, and again, it is not the optimum way to go, I AGREE WITH YOU, but it is not bad
    in a pinch.:1:
  • 05-29-2011, 06:06 PM
    N. Abstentia
    Yeah I didn't say it couldn't be done...I just said it couldn't be done right!
  • 05-30-2011, 04:20 PM
    pixelthis
    Quote:

    Originally Posted by N. Abstentia View Post
    Yeah I didn't say it couldn't be done...I just said it couldn't be done right!

    It can be done in a way that works, which is always "right"
    even if sometimes not optimum.
    IN ALL THE TIME I ran a sub like this I never had a problem.:1:
  • 05-31-2011, 05:14 AM
    GMichael
    Quote:

    Originally Posted by pixelthis View Post
    It can be done in a way that works, which is always "right"
    even if sometimes not optimum.
    IN ALL THE TIME I ran a sub like this I never had a problem.:1:

    But the OP was asking which was better. Using the amp in your/his receiver is surely not the better choice, unless he has no choice.
  • 05-31-2011, 11:27 AM
    pixelthis
    1 Attachment(s)
    Quote:

    Originally Posted by GMichael View Post
    But the OP was asking which was better. Using the amp in your/his receiver is surely not the better choice, unless he has no choice.

    By all rights this method should be like one of those tire fix
    spray cans, because when a sub goes out its not always
    convenient
    HOWEVER days turned into months, and this "fix" worked fine
    THE truth is that a sub is probably never going to need even
    the paltry 125watts put out by my receiver channel . And levels,
    etc were easy to adjust.
    And this was a sub that came with a BASH 600w plate amp(its
    now running on a 130w). It may go against instincts, but at the end of the day, an amp is really just an amp.
    I know that the true power of a receiver is gaged by its power
    supply, how many amps is available to be distributed to each
    channel, and the power claims are usually about as optimistic
    as TREASURY forecasts, but I REALLY NEVER HAD A PROBLEM.:1:
  • 05-31-2011, 11:40 AM
    GMichael
    Would you rather drive cross country with a tire that has a can of fix-o-flat in it or on 4 new tires? Sure, you may never have a problem with that tire, but if you had a choice, which would you pick?